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  <title>Document</title>
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<body>
  <script>
    // 1.八进制  0~7 数字前面加0表示八进制
    var num1=010;
    console.log(num1);   //8
    var num2=012;
    console.log(num2);   //10

    // 2.十六进制 0~9  a~f  数字前面加 0x 表示十六进制
    var num3=0x9;
    console.log(num3);   //9
    var num4=0xa;     
    console.log(num4);   //10
  
    //3.非数字
    console.log('Pink'-100);   //NaN
  </script>
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